Airplane having a variable lifting surface



Jan. 6, 1931. J. GERl N 1,787,517

AIRPLANE HAVING A VARIABLE LIFTING SURFACE Fil ed Nov. 30. 1928 a She ets-Sh eet 1 Jan. 6, 1931. J. GERIN AIRPLANE mwme A VARIABLE um'me szmmca 8 Sheets-Sheet 2 Filed Nov. 30, 1928 FigZ Jan. 6, 1931. J. GERIN 1,787,517

AIRPLANE HAVING A VARIABLE LIF'I'ING SURFACE Filed Nov. 30, 1928 8 Sheets-Sheet 3 &

V/IIIWIIIIIII Jan. 6, 1931. J. GERIN 1,787,517

AIRPLANE HAVING A VARIABLE LIFTING SURFAbE Filed Ndv. 30, 1928 8 Sheets-Sheet 4 AIRPLANE HAVING). VARIABLE LIFTING SURFACE Filed Nov. so, 1928 s Sheets-Sheet 5 Fig/ 2 Jan. 6, 1931. J E I I 1,787,517

AfRPLANE HAVING A VARIABLE LIF'I'ING SURFACE Filed Nov. 50, 1928 8 Sheets-Sheet 6 nv veN Ta R g777wa Jan. 6, 1931. t J. GERIN 1,787,517

- AIRPLANE HAVING A VARIABLE LIFTING SURFACE v Filed Nov. 50, 1928 8 Sheets-Sheet 8 Patented Jan. 6, 1931- PATEN OFFICE JACQUES GERIN, or rants, runes muslin HAVING A VARIABLE ammo sum-eon Application filed November 30, 1928 Serial No. 822,941, and in France December 18, 1927.

The present invention relates to airplanes having a a variable liftingisurface and relates to a type of variable wing surface applicable to these airplanes and allowing, during flight,

' to modify, at will, the surfaces of the wings of an airplane in view of obtaining the maximum difference between the speeds'during flight and the speeds upon landing, and at the same time to facilitate the flying off of 10 heavily loaded machines.

This variable surface is characterized in thatit is constituted by a supple wall reinforced by ribs arranged in the direction of its depth and transversely secured to distortable 15 bonds, such as chains having jointed links which wind on the one hand on an operating drum and, on the other hand, can move in slides arranged on fixed parts of the airplane, those fixed parts being, preferably, lifting surfaces of the airplane.

A form of constructlon of a variable sur face such as above set forth and which, for the moment, seems to present numerous advantages, is characterized, moreover, in that 25 the axis of its winding drum is arranged at' right angles to the direction of development of this surface, the chains secured on some of the fixed lifting planes of the airplane, an airplane hav- 9 ing several movable surfaces the displacements of which are associated, so as to preserve the balancing conditions of the airplane, whatever may be its lifting surface. a

v The transverse balancing of the airplane always automatically ensured, if the variable surfaces are arranged groups relatively to the axis of advance of the machine, these groups being controlled The balancin in the longitudinal direction can be obtamed by the movable surfaces alone or with the adj unction'of movable-plane provided preferably, adjacent to the empenby an operating mechanism which preferably is kinematically connected to the control of the movable or variable surfaces. I Theaccompanying drawing illustrates, by

5 way of example only, various forms of construction of-the movable varlablesurfaces and to the guide slides of for controlling the "wingfflap. in symmetrical r pair from one and the same mechanism.v

nage, and the-incidence-ofwhich is modified...

above characterized in their general arrangement.-

Figures 1 to 3 are transverse sections ofan airplane wing provided with variable surfaces. 1

Figure 4.- is a diagrammatic elevation of an airplane in its entirety, provided with variable surfaces.

Figures 5 and 6 are diagrammatic views of control devices relating to this airplane.

Figure 7 is a plan view of a wing tip. Fi ure 8 is a corresponding end view, with part roken away.

' Figure 9 is, on an enlarged scale, a cross section according to A-A of Fig. 8.

Figure 10 is a cross section, on an enlarged scale, of a front slide for guiding'the chains of the variable surfaces.

I Figure 11 is a-similar view of a front slide.

Figure 12 is an elevation of a movable surface, wound on its '0 crating drum.

- Figure 13 shows, in partial section, a front chain of movable surface, Figure 14 being a corresponding side view.

Figure 15 1s a artial longitudinal section of a movable sur ace at the level of a rib. Figure 16 is asi m-ilar view of an end rib. Figure 17 is a horizontal section of arear chain of movable surface and of-its pulling device. 1

Figure 18 is a plan view of a wing end with movable surface and warping air flap.-

Figure'19 is a corresponding elevation.-

Figure 20 is a side view of the mechanism as Figure 21 is an a lse'ction of a slide end of the wing ofFi'g; 18 i a Figure 22 is a cross section according to B- Bof Fig.21. Figure 23 -is,.on anenlarged scale, a sec.- tion according to Fig. 1.8.. v Figure24 is an axil section of an end of adrum for winding up a movablesurface:

view the winding of a movable surfage on itsdrum.- 3 3 A Figure .26. is a diagrammatic viewpf a mechanism for controlling two drums.

Figure 25 is a diagram showing in"en d g Figure 27 is a foot control mechanism of the winding up drums.

Figures 28 and 29 are diagrammatic plan views of an airplane provided with movable surfaces in accordance with the invention.

Figure 30 is a diagrammatic plan view of .the front part of an air lane, with a lifting plane the V of the lea ing edges of which is adjustable.

Figure 31 is an elevation of a high speed airplane.

Figure 32 is a corresponding plan view.

As indicated in the foregoing, an airplane, provided with variable surfaces inaccordance with the invention, has, according to its type, a number of fixed lifting planes. With each of these fixed planes, or with some of them only, are combined the variable surfaces which can be either withdrawn within cavities sheltered from the contact of the relative wind of the airplane, or extended for increasing, at will, the lift per unit of area of the airplane.

The fixed planes with which are combined the movable surfaces, are provided with slides arranged in the direction of the span of the airplane and intended to guide chains, formed of jointed links, which con nect transverse ribs adapted to reinforce the movable surfaces when they are extended. Thus, in Fig. 1, is shown in section afixed plane 1, having a spar 2, of any suitable construction, and a leading edge 4 which, preferably, contributes to the resistance of the plane. The portion of the wing, at the rear of the spar 2, is hollow and throughout its length extend slides 5 and 6 between which can move ribs 3 which extend throughout the depth of the variable surface and are suitably distributed throughout the length of the latter. In Fig. 2, the ribs 3 of the variable movable surface move, at their two ends, between two grou s of slides 5 and 6 belonging to two fixed p anes 1 and 1'. This arran ement is more particularlyused in case t e variable surface is of great depth.

In case of a very important length of its cord, the variable surface. can be sustained by a control slide 7 provided in a lifting plane 8 situated between the two above mentioned planes 1 and 1', as shown in Fig. 3. In the example of construction of Fig. 1, the ribs 3 are so devised as to be rigid on a portion oftheir length, but as to be able of resiliently distorting at their portion 3. These ribs are wrapped up and suitably secured, by gluing or other means, between layers of canvas or other supple walls 9, as -shown in Fig. 15.

In Fig. 7, it will be seen that the ribs 3 are secured, at their front part, on two chains 10 and 11 composed of links pivoted about Y junction axes 12. The ribs are, for that purpose, provided with cheeks 13 which fit between two consecutive links of the chains and are pivoted on the axes 12 of the said links. The links of the chains are guided in the above mentioned slides 5 and 6 and which are illustrated in detail in Fig. 8. The slides 5 are constituted by suitable section members rigidly secured on the spar 2, whilst the slides 6 are, preferably, connected from place to place by rigid cross members, or otherwise, to the spar 2. The junction axes 12 acting as rollers bear laterally on the section members of the slides, so as to hold the movable surfaces transversely to the fixed planes, along which they unfold (Fig. 10). The variable surface slides between the fixed trailing edge 14 of the plane 1 and a trailing edge 16 of a movable surface 17 pivoted at 15 on the plane 1 and, preferably, returned to Withdrawal position by springs 17 (Fig. 11) when the variable surface is not extended. At one of its ends, the movable surface with its chains 11, its ribs 3, and its canvas layers 9, Winds on a drum arranged in a recess sheltered from the relative wind of the airplane. One of these drums is shown, in its general aspect in Fig. 12, the variable surface being shown completely wound up. a i

. At the free ends of the chains are attached cables 18 which pass on pulleys 20 suitably supported relatively to the fixed plane 1, these cables winding on a grooved pulley 21 arranged on the driving shaft 22 of the winding drum, but angularly connected to the same, through the medium of a torsion spring 23 the function of which is to ensure a permanent tension of the cables (Fig. 24). The groove for winding up the cables 18 on the pulley 21 is projected in spiral form on a plane at right angles to the axis 22, so that, when the movable surface winds on its drum or unwinds from the latter, the linear speeds of translation of this surface and of the pulling cables are substantially equal. 4

As shown in Fig. 25, when the movable surface winds on its drum, the ribs 3 are juxtaposed or superposed according to the zone wound up,'so as to reduce the cumbersomeness to the minimum. For allowing an exact superposition of the ribs, itis possible, at the places where it is necessary, to replace one and the same rib by two spaced ribs,

the moment of inertia of which corresponds and the same power means. Thus, as shown in Fig. 26, on the axes 22 of two drums are 1n engagement a drivin secured equal pinions 24 constantly earin-g together and with which can be put secured on the shaft an electric motor mounted on a frame-rocking about an axis 25;

y ting on a lever 26,- thepinion 19 is brought in contact with one or the other of the inions 24 for obtaining the winding up or t e unfolding of the variable surfaces. The intermediate position of the pinion 19 corresponds tothe condition of rest of the drums. Obviously it is possible to drive the drums by any other mechanism and, for instance, by means of an intermediary provided with a clutch adapted to throw it in engagement or not with a suitable rotating part of oneof the engines propelling the "airplane.- Use can also be made of a control set in action by the muscular force of the pilot or of a passenger.

The drums for winding up the flexible surfaces maybe rotated from a member upon which" isexerted 'amu'scular action from the pilot of'the airplane. In Fig. 27, is shown a-sliding member 27 guided in a slide 29 secured on a retracted by one or moresprings 32. The sliding member 27 is connected by a connecting rod 30 to a crank plate 31 which, by

means of'any suitable gearing, drives the drum. The pilot, with its foot bearing upon faces.

associate the parts 28 of the sliding member 27, imparts to the same a reciprocating movement in order to rotate the crank-plate31.

Figure 4 shows a biplane, having an upper plane 1 and a lower plane 1, with which is combined a variable surface of'the kind of that which has just been described in the foregoing. The drums of the variable surfaces are arranged inthe fuselage of the machine and can be'driven by a mechanism such as that just described. When the variable surfaces are extended, the conditions of lonitudinal balance of the airplane are modied from the fact of the displacements of the centers of thrust.

For correcting these displacements, planes 33 are arranged at the empennage, the incidence of these planes being mcdified according to the length of'unfolding of thesur- This modification of the incidence can be effected bymeans of a special control, or, referably, by. means of a control d with that of the drums for winding up the variable surfaces. A suitable mechanism can, for instance, be interposed between the control of the drums, and a rocking transmission member 34 (Fig. 5),

connected by cables to a'lever 35 coiiti'olling the axis 36 of movement 'of the surfaces.

This connection can be effected by means of pinions 37 and a chain 38 (Figs 6).

The warping wing flaps of airplanes propinion 19 rigidly folded, the

fixed part of the airplane andwith a suflicient play in equivalent means, on

vided with the movable surfaces forming venient y rovided on the fixed lifting lanes of t e airplane. But when the suraces are unfolded, the wing'flaps,which are sufliclent for the speeds of the airplane having a reduced lifting surface, can no longer be suflicient when the lifting surface .is increased. In this case, it is necessary to warp a portion of the variable surfaces. For that purpose, use ma be made of the arrangement illustrated in Figs. 7 and 18 to 23. At each end of the fixed plane 1 is arranged a wing flap 39 prises a socket 40 mounted on a pivot 40 rigidly secured on the fixed plane. the variable surfaces are completely, unend rib 3 fits between two outwardly extending flanges 39" of the wing flap 39, so that the oscillations of the latter, about its pivot 40, are transmitted to the variable surface thereof. i

For allowing this warping and delimiting its range, the slides 5 and 6 are interrupted before reaching the end of the fixed plane 1 and extended in end parts 5 and 6, respectively connected by ball and socket joints to the parts 5 and 6 and to the wing flap 39.

' For that purpose, the slide 5, for instance, has; at its end, a box 5 (Fig. 21) in which fits a spherical member 41 ofithe part 5. The latter, at its other end, is a second spherical member 5 which fits in asleeve 42 of the wing flap, a spring 43 being interposed between a seat 44 bearing on the spherical member 5 and a flange or a bottom of the sleeve, for allowing the device to adapt itself to, the variations of distance between'the sleeve 42 and the slide 5, upon warping. Of course, the chains are made their elements for adapting themselves to the transverse torsions imparted to themby the warping.

The actuation of the wing flap is effected by any suitable devices and, for instance, and as illustrated, by means of afork'45, pivoted at 46 on the ated by'cables 47, in theknown manner. The fork engages a finger 48 secured in a lining 49 (Fig.

the socket 40.

In the foregoing it has been indicated that the drums for winding up the variable surfaces were arranged 'n recesses or in places sheltered from the relativeiwind of the airplane. According to the type of the airplane to which these variable surfaces are applied, use may be made of extremely various solutions concerning'the places to be'reserved for the drums.

In Figures 28 and 29, which showplan views of biplanes, the drums 51 are arranged When 7 for warping the end fixed plane 1 and actu 23) and screws 50, or.

the framework of which comprovided with a which are mounted the variable surfaces.-

For that purpose, use can be made, among other utilizable devices, of the assemblage illustrated in Fig. 30. The lifting planes 1 are pivoted about axes of the fuselage and can pivot about these axes at the same time as the frames carried by the drums 51 of the variable surfaces. These frames are, for instance, attached to nuts 71 mounted on screws 72 and 73 having reverse pitches, simultaneously actuated by a shaft 74 and bevel pinions 7 5 which can be thrown in gear at will with any suitable engine. It is also possible to modify the position of the centers of thrust in view of maintainin the longitudinal balance of the airplane, w iatever may be its lifting surface.

It is also possible by construction (Figs. 28 and 29) to incline the slides of variable planes so that they form a negative sagging, for the purpose of obtaining, by displacement of the center of thrust, the permanent balancing of the airplane.

The invention which mainly concerns variable surfaces of the kind indicated in the foregoing and defined by the above mentioned features, can obviously lend itself, according to the conditions of adaptation, to extremely variable forms of construction. All these constructional modifications, which do not modify the principle of operation nor the object sou ht for, are obviously included in the scope 0 the invention.

What I claim as my invention and desire to secure by Letter Patents is:

1. In an airplane having a variable lifting surface, rigid lifting planes, flexible lifting planes comprising a supple wall provided with ribs arranged in the directionof flight of the airplane, drums for winding and unwinding the said flexible planes, means upon the rigid planes for guiding the said ribs when the flexible planes are moved along the rigid planes for varying the lifting surfaces of the airplane, means for operating the drums and for stretching the flexible planes.

2. In an airplane having a variable lifting surface, rigid lifting planes, flexible lifting planes comprising a supple wall reinforced with ribs arranged in the direction of flight of the airplane, chains connecting the said ribs together guiding means upon the rigid planesv for the said chains, operating drums for moving the flexible planes and located in closed parts of the airplanes, cables .con-

,1 nected to the free end of each flexible plane,

guiding pulleys for the said cables upon the pulley provided with rigid planes, a drivin a helical groove for the cable and angularly connected to an operating drum in order to stretch the said flexible plane, means for rotating the operating drums.

3. In an airplane having a variable lifting surface, rigid lifting planes or wings, flexible lifting planes comprising a supple Wall provided with reinforced ribs arranged in the direction of flight, chains connecting the said ribs together, guiding means upon the rigid planes, for the said chains, operating drums for moving the flexible planes and located in closed parts of the airplane, a cable connected to the free end of each flexible plane, guiding pulleys for the said cable upon the rigid plane, a driving pulley provided with a helical groove for the said cable and angularly connected to an operating drum in order to stretch the said flexible plane, and means for connecting the wing flaps of a rigid wing with the free end of the flexible plane movable along the said wing.

4. In an airplane having a variable lifting surface according to claim 3, a rigid wing having sliding longitudinal girders for guiding the transverse ribs of a flexible plane, balls-joints near the ends of the said sliding members in order to permit distorsions of the latter, a Win flap at the end of the win a pivot upon t 1e latter for the said wing ap, and parts on the same to engage the e ge of the -flexible plane when it is wholly spreadout. 5. In an airplane having a variable lifting surface according to claim 1, rigid wing pivoted upon a fuselage of the airplane in order to be moved substantially horizontally, a frame rigidly secured to the said wing and carrying an operating drum for the movable flexible plane guided in sliding members of the wing, means for moving the said wing about its pivot, at the will of the pilot.

In testimony whereof I have signed my name to this specification.

JACQUES GERIN. 

